Mass spectrometers may be used to detect ions according to their mass-to-charge ratio. Certain spectrometers may trap ions for analysis such as electrostatic ion trap mass spectrometers. Electrostatic ion trap spectrometers may confine ions of different mass-to-charge ratios and kinetic energies within an anharmonic potential well. The amplitudes of oscillation of the confined ions are increased as their energies increase, due to an autoresonance between the AC drive frequency applied and the mass-dependent natural oscillation frequencies of the ions, until the oscillation amplitudes of the ions exceed the physical dimensions of the trap and the mass-selected ions are detected, or the ions fragment or undergo any other physical or chemical transformation.
There is a need in the field for mass spectrometers, including electrostatic ion trap spectrometers, that provide improved signal intensity and mass resolution to allow for faster mass scan rates and instrument response times. The present invention meets these needs.